On-board monitor



FIG. 1 is a front elevational view of an on-board monitor showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a perspective view thereof.

The broken lines illustrate portions of the on-board monitor that form no part of the claimed design. 

CLAIM The ornamental design for an on-board monitor, as shown and described. 